We have made substantial progress on several of the Specific Aims proposed in 2006 and further focused future directions toward the challenging long-time aim of understanding eukaryotic channel gating by ligands, particularly in the Acetylcholine Receptor (AcChR). A major subtext has always been to attempt to define structures of eukaryotic and human proteins because of their importance for drug discovery. Towards this goal, we determined two of the first four structures for human membrane proteins, using expression in human cultured HEK293S cells.